The invention relates to claw toothing for a gearbox or the like, of which the claws are designed with an undercut and, viewed in cross-section with respect to the longitudinal axis of the claws, have a flat or convex roof profile.
Such claw toothings, in particular in gear-shift sleeves and gear wheels in motor vehicle gear boxes, are subject to great wear. The roof profile of the claws, which plays an important role for the first contact in the meshing phase, is therefore to be designed in such a way that the engagement occurs quickly and as much as possible without friction. Moreover, the quality of the claw toothing is determined decisively by the design of the sides; by the sides forming an undercut, a reliable engagement is ensured.
From the U.S. Pat. No. 3,550,738 a synchronizing claw clutch coupling is known in which individual claw elements protrude cam contour-shaped. In this way, shifting gear at high speeds becomes possible, without causing edge wear on the claws which occurs with conventional couplings. The known claws have, according to FIGS. 4, 5; 8, 9 and 12, 13 respectively of this U.S. Pat. No. 3,550,738, sides with slight undercuts as well as a flat or convex roof profile, viewed cross-sectionally to the longitudinal axis of the claw. The plan view shape of the claws in this case tapers into a wedge shape towards the axis of rotation of the claw toothing and the generatrices of the claw shape in the longitudinal direction of the claw are straight lines which in the area of the sides run according to this wedge shape.
In addition, a motor vehicle coupling which responds quickly and with low friction is known (U.S. Pat. No. 5,524,738), the claws of which are undercut on both sides; the claws, viewed in cross-section with respect to the longitudinal axis of the claws, have a flat or convex roof profile. Also here, the plan view of the claws tapers into a wedge shape towards the rotational axis of the claw toothing and the generatrices of the claw shape are at least in the area of the sides in the longitudinal direction formed by straight lines which run according to the wedge shape. Hereby, a shifting of gear at high speeds should be possible with little wear.